Sixteen countries performed and were whittled down to ten based on the audience voting (full list below).

One of the biggest showdowns of the night, however, was between Ukraine and Russia. When the Russian entry was voted through to the final, the sister act was met with boos from the crowd. The situation in Crimea has caused a headache for Eurovision vote counters, who were unsure whether votes called in from the area should count as Ukrainian or Russian.

"If the people in Crimea remain on a Ukrainian mobile network, as they are now, their votes will count for Ukraine," Eurovision spokesperson Jarmo Siim told the Wall Street Journal (WSJ) on Friday.

Incidentally, both the song by the Russian entry - the Tolmachevy Sisters - and the song by Ukraine's Mariya Yaremchuk were written by Swedish songwriters.

The tunes were penned by John Ballard and Sandra Bjurman respectively, noted the Skånskan newspaper.

The favourite to win this year is Armenia, whose contestant will sing first on Tuesday night. Oddschecker tipped Sweden for second, followed by the UK and Ukraine.

Full list of contenders who made it through:

Armenia: Not Alone sung by Aram MP3

Sweden: Undo sung by Sanna Nielsen

Iceland: No Prejudice sung by Pollapönk

Russia: Shine sung by Tolmachevy Sisters

Azerbaijan: Start A Fire sung by Dilara Kazimova

Ukraine: Tick-Tock sung by Mariya Yaremchuk

San Marino: Maybe (Forse) sung by Valentina Monetta

Netherlands: Calm After The Storm sung by The Common Linnets

Montenegro: Moj Svijet sung by Sergej Ćetković

Hungary: Running sung by András Kállay-Saunders

The second semi-final will be held on Thursday, May 8th, with the grand final to play out on Saturday night. See the official Eurovision site for more details.